For almost a century, heroin addiction has been a core element of the illicit drug use problem in Canada. Recently, however, isolated reports have pointed to substantial increases in prescription opioid abuse.

To determine the impact on usage patterns among street drug users, Fischer and colleagues analyzed data from the OPICAN study (a multisite study of drug use patterns among illicit opioid users across Canada). They found that heroin use has become an increasingly marginal form of drug use and that, instead, use of prescription opioids is now the predominant form of illicit opioid use.

The authors discuss several crucial implications of these changes in usage patterns, including the fact that prescription opioids used by street drug users are obtained directly or indirectly (e.g., through friends or partners) from sources in the medical system. They suggest that adjustments may be required to opioid addiction treatment programs.

In a related commentary, Wainberg discusses the implications of this study and the need for enhancement of detoxification programs.